AR rail without removing front sight?

I was wondering if there was any rail out there that I could attach to my AR without removing the front sight/gas block. I built my first AR on Monday for $470 and am already eyeing some upgrades, but I would like to avoid removing the gas block at all costs if possible. Right now I'm using the standard A-2 hand guards. Thanks for any help y'all!

The easiest quad rails to install are for example those like the Surefire Model M-73 type two piece quad rail. Which by the way would just fit on your M4 Hand Guard Length Rifle. Many companies are making them and you can put them on your rifle simply by removing your standard M-4 Hand Guard that you have. But one thing you must do when you install them is re-zero your rifle because they will change the barrel harmonics of the barrel. Causing it not to be zeroed as it was previously. It is simple! Put them on as instructed and re-zero your rifle!

03

__________________
The Constitution is not an instrument for the Government to restrain the people. It is an instrument for the people to restrain the Government!
*Patrick Henry

“Americans have the right and advantage of being armed. Unlike the people of other countries, whose leaders are afraid to trust them with arms.”
James Madison. Author of the 2nd Amendment

I added one. I decided to neatly drill and tap my rail for a cleaner mount, but they come with the necessary hardware.
I added one on top for a 45 degree light mount. didn't want sharp edges around the rest of the fore grip.

The Cheapest solution is a Magpul MOE handguard and a polymer rail section.

__________________Assumption is the mother of all ****ups.Know what you know, Know what you don't know. -Paul Pedzolt"Jack of all trades, master of none, though oftentimes better than master of one" -Mynshul